I can't see the saddle or sickle feathers in these pictures (lower back and tail). It would be the best way to tell. Even if the comb is still small, you would start to see longer feathers on and just above the tail and on the neck for a cockerel. Usually at 4 months you'll start to hear crowing too.
There have been some throbacks to a genetic anomoly which produces what "th' Ol' Lady refers to as a "heneroo".
Others call 'em "hennys", A rooster that looks like a hen.
Not certian but I think it comes from breeding too closely for too long.